The invention relates to a driving circuit for selectively displaying, on the screen of a cathode ray tube, a prespecified set of characters, wherein the characters are either displayed having a nominal size or displayed having a height that is twice that of the nominal size.
Many industrial processes and particularly machine processes performed by numerically controlled machine tools require by their very nature highly complex and non-repetitive instructions to command a tool to machine the complex outlines of a workpiece. However, many of the processes or tooling operations require repetitive yet simple instructions to generate the required series of process or machine tool movements.
Prior controllers have required a programmer, having numerical control, machining and programming skills to generate a tape defining the unique instructions, i.e. part program, containing the required tool displacements and machine tool commands to transform the workpiece into a finished product. These part programs are often generated using larger general purpose computers and the like.
In contrast the present invention has taken advantage of the recent widespread commercialization and availability of sophisticated microprocessors. More specifically, the resulting system is applicable to the class of numerically controlled processor called manual data input controllers, as well as industrial processors generally. The present invention yields a relatively inexpensive and smaller unit, thereby permitting the system to be pendently mounted to the machine tool. In addition, the present invention eliminates, for many purposes, the need for a skilled programmer.
This is accomplished by including within the system a number of pre-programmed, normalized part programs containing instructions to command the machine. A particular program is selected by the operator via communications through the keyboard or some other similar device. In response to this selection, the system enters a conversational mode thereby informing the operator of the data required to execute the selected stored program. As can be seen from the above, the operator need not be conversant in computer programming or skilled in the operation of numerically controlled machines. The operator need only follow the requests received from the system. In addition, the need for generating computer aided part programs, as utilized in prior numerically controlled systems is considerably alleviated. The operator can, with minimal skills, link various pre-programmed part programs to generate non-repetitive sequence of events or may directly create an additional part program by manually inputting a sequence of instructions in the system.
It therefore is an object of the present invention to provide a microprocessor based process control system.
It is another object of the present invention to provide a process control system having a central processor that generates a 16 bit word and is capable of interfacing with 8 and/or 16 bit peripheral information transfer modules including keyboards, tape recorders and cathode ray tubes.
It is object of the present invention to provide a display circuit for the process control system to display to the operator the current status of prespecified functions of the machine or process being controlled or performed, thus permitting the operator to concentrate his efforts on monitoring the machine while concurrently receiving the displayed information.
In conjuction with the last mentioned object, it is a further object of the present invention to aid the operators tasks by optionally displaying to the operator certain parameters in an enlarged format.
It is another object of the present invention to provide an interactive microprocessor based control system for a machine tool.
In conjunction with the last named object, it is a feature of the present invention to free the operator from the requirement of generating complex and lengthy part programs which control the machine tool, by including within the present system a variety of resident, normalized, part programs of frequently used machine tool functions, requiring only input data which is displayed by the system to the operator and which is then manually input to the system in response thereto.
These and other objects, purposes, features and advantages are accomplished in accordance with the teachings below.